Apparatus for detecting profile of band plate

ABSTRACT

In a rolling mill having means for changing the flatness profile, such means are controlled by a detector that engages the band coming from the rolling mill under tension to determine the tension at a plurality of points transversely across the bands, which tension distribution is correlated to the band unevenness, when relaxed, and convert the thus determined tension into signals that are compared with reference values for operation of the means to control the plate unevenness or flatness. The detectors preferably convert the tension at the plurality of locations into moments that may be measured with load cells interiorly of closely adjacent freely rotating rings, wherein the tension component exerted on the rings is transferred to a pivotal mounting for the ring support structure to thus produce the moment. The signals on the left side of a band center line are compared with the signals on the right side; the signals from detectors between the band edges are compared with a reference signal produced by summing all of the signals; and the signals from the edge detectors are compared with a reference signal produced according to the proportion of the band edge engaging the edge detectors.

United States Patent [1 1 Ishimoto [451 Sept. 2, 1975 APPARATUS FOR DETECTING PROFILE OF BAND PLATE [75] Inventor:

[73] Assignee: Hitachi, Ltd., Tokyo, Japan [22] Filed: Mar. 5, 1973 [2]] Appl. No.: 338,274

Masaki Ishimoto, Hitachi, Japan [30] Foreign Application Priority Data Primary Examiner-S. Clement Swisher Attorney, Agent, or FirmThomas E. Beall, Jr.

[57] ABSTRACT In a rolling mill having means for changing the flatness profile, such means are controlled by a detector that engages the band coming from the rolling mill under tension to determine the tension at a plurality of points transversely across the bands, which tension distribution is correlated to the band unevenness, when relaxed, .and convert the thus determined tension into signals that are compared with reference values for operation of the means to control the plate unevenness or flatness. The detectors preferably convert the tension at the plurality of locations into moments that may be measured with load cells interiorly of closely adjacent freely rotating rings, wherein the tension component exerted on the rings is transferred to a pivotal mounting for the ring support structure to thus produce the moment. The signals on the left side of a band center line are compared with the signals on the right side; the signals from detectors between the band edges are compared with a reference signal produced by summing all of the signals; and the signals from the edge detectors are compared with a reference signal produced according to the proportion of the band edge engaging the edge detectors.

27 Claims, 18 Drawing Figures PATENTEDSEP zins q 902 363 sum 1 o a PATENTEDSEP 2191s SHEET 2 [IF FIG.5

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PATENTEM 2975 3,982,363

seam 8 BF 8 lOl i041. l04lR I05 I I09 ADDER AMPL IO6L JAjJAe JAB JAB J 5 JA' SELECTOR CALCULATOR us I 10 I I l PRESETTER APPARATUS FOR DETECTING PROFILE OF BAND PLATE BACKGROUND OF THE INVENTION The present invention relates to apparatus for detecting the profile of a band plate, particularly for continuously detecting the profile of a metal strip during a rolling process conducted on the metal strip, which detection may be used to control the rolling process.

In the last decade, the automation tandem rolling mills has been swiftly promoted, and at present, most new tandem rolling mills are established to be operated through AGC systems (automatic gauge control systems) or automatic control systems with computers.

In such automatic production equipment, particularly for rolling, the most important object is the preciseness with which fluctuations or disturbances are detected in the object to be controlled. The subject is more important in cold rolling mills for rolling a thinner and more accurate plate than in hot rolling mills for rolling rather thick plate.

For cold rolling mills, the most important matters to be concerned with are the thickness control and flatness control (profile control). The flatness control is the most difficult of these two, so that the technical development in this field is of particular importance at the present. Roll bending methods developed a few years ago are effective to control flatness, however they have not been sufficiently effective in rolling mills todate, because there is no apparatus for detecting flatness or profile with high reliability to operate such roll bending apparatus. Accordingly, development of the apparatus for detecting flatness with high reliablility and practical use is desired.

One of the reason it is difficult to put into practical use a high accuracy flatness detecting apparatus to be used with a cold rolling mill is the singularity of cold rolling reduction itself. It is a characteristic of the cold rolling mill that the strip must be under considerable tension, thus, the surface of the strip which may be wavy under conditions without tension will be appear to be flat when the tension of rolling is acting upon it. Therefore, it is ineffective to use a known surface variation measuring device which will only function to detect uneven surface as a flatness detecting apparatus for cold rolling reduction, because of the abovementioned tension.

For this reason, more accurate detecting of the profile of the strip during cold rolling must be done by detecting some variable proportional to the surface flatness, rather than by directly detecting the surface flatness.

According to studies made up to now, it has already been found that the best proper variable correlated to the surface flatness is the stress distribution of the strip undergoing rolling in its width direction, relative to the direction of travel for the strip. Considering a strip that is being cold rolled, and which would not be flat if in its unstressed position, there will be a portion across its width that would be flat, and adjacent portion that would not be flat, if the tension of rolling were not present, that is if the strip were in its relaxed condition. Under the tension of rolling, the above-mentioned portion that would not be flat will have a tensile stress acting upon it that will be considerably less than the tensile stress acting upon the above-mentioned portion that would be flat. Thus, although the strip under tension would be flat, the uneven portions will have less tensile stress in them than the even portions, so that the stress distribution across the width of the strip under tension will be proportional to the flatness profile across the strip if the tension were removed.

Accordingly, strips are able to be reduced flatly in theory through detecting stress distribution along the width direction of the strip. Therefore up to now, various apparatus for detecting; flatness based on the above-mentioned theory have been published: for example, Japanese Pat. Publication No. 20181/1967; Japanese Publication No. 21209/1969; US. Pat. No. 3,334,508; and French Pat. No. 1,486,208.

The above-mentioned known apparatus for detecting flatness are effective for measuring the strip surface with proper shape, however they have faults as will be stated here and after. They are not sufficiently reliable for practical use. Namely, in the two-split rolled type apparatus for detecting flatness disclosed in Japanese Patent Publication No. 2018 l l 1967, the surface profile (tension distribution) with a plurality of uneven portions in the width direction of the strip is not able to be detected, because the apparatus is provided with only two detecting rolls.

In the multi-split rolled type apparatus for detecting flatness as disclosed in Japanese Pat. Publication No. 21209/ 1969, the detecting portion rotates and the apparatus uses slip rings in order to derive control signals from the detecting apparatus. This apparatus will have considerable errors in its detection and further is subject to easy breakage so that it is not reliable.

Apparatus for detecting flatness as disclosed in US. Pat. No. 3,334,508 is provided with a plurality of detecting rollers and is different. from the apparatus disclosed in Japanese Pat. No. 20181/1967 in that the former is provided with a bearing for each one of the de tecting rollers, therefore, the apparatus of the US. patent is of such a construction that it will spoil the strip surface, since there are large gaps between the detecting rollers.

With the apparatus for detecting flatness as disclosed in French Pat. No. 1,486,208, the construction is such that the surface profile of the strip (the tension or stress distribution) is converted into pressure of a control fluid, so that the apparatus needs to keep the fluid pressure constant and requires very accurate apparatus for measuring fluid pressure. Therefore, this apparatus is quite complicated and has the considerable detect that it is in danger of and subject to oil leakage.

For the above reasons, the apparatus known todate have not satisfactorily meet the needs of strip profile detection during rolling, particularly during the cold rolling process where considerable tension is applied to the strip.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome the above-mentioned disadvantages of the known prior art and provide apparatus for detecting the profile of band plate, which apparatus is able to accurately detect flatness for profile of the band plate or strip without spoiling the surface of the band plate by arranging a plurality of detectors very closely adjacent ble parts, for high reliability. A plurality of ball bearings I forthe moving parts are provided so that the apparatus may operate stability at high speeds. The construction of the various parts is such that assembly and disassembly for maintenance of the detectors is greatly facilitated.

Further, the detector is preloaded so that it will not be responsive to impulse loading.

A plurality of individual detectors are arranged adjacent each other transverse to the width direction of the moving band plate or strip, with each of the detectors including means for converting the component of tension in its contacting plate portion into a turning moment and further means for measuring the reaction of the turning momentto produce a control signal.

A control circuit associated with the detectors is so constructed that the stress distribution of the band plate is found and based on the whole or total tension component over the width of the band plate and the tension component of a portion of the strip.

A BRIEF DESCRIPTION OF THE DRAWINGS Further objects, features and advantages of the present invention will become more clear from detailed de scription of the preferred embodiment with variations, as shown in the attached drawing, wherein:

FIG. 1 is a somewhat schematic elevation view for an arrangement of a rolling mill and a profile detectingapparatus according to the present invention;

FIG. 2 is a view of an arrangement similar to that of FIG. 1, with modification;

FIG. 3 is a schematic frontview showing one embodiment of the apparatus for detecting the profile of band plate according to the present invention that may be used in the apparatusof FIG. 1 or FIG. 2;

FIG. 4 is a side elevation view of the apparatus of FIG. 3, taken along line IV-IV;

FIG.'5 is anenlarged sectional view taken along line VV of FIG. 3;

FIG. 6 is a fragmentary sectional view. taken along line VI-VI of FIG. I

FIG. 7 is a side cross-sectional view of another embodiment of the present invention similar to the view of FIG. 5, which may be used in the apparatus of FIGS. 1-3;

FIG. 8 is a fragmentary sectional view taken along line VllI-Vlll of FIG. 7;

FIG. 9 is a fragmentary sectional view taken along either of the lines IX-IX of FIG. 7;

FIG. 10 shows a further embodiment of the present invention, in a view similar to FIGS. 5 and 7, which may be used in the apparatus of FIGS. l-3;

FIG. 11 shows a further embodiment, which is a variation of the embodiment of FIG. 5;

FIG. 12 discloses a further embodiment of the pres ent invention, in a view similar .to that of FIG. 5;

FIG. 13 shows a variation in the embodiment of FIG. 12;

FIG. 14 shows an embodiment of the present invention in a view similar to that of FIG. 5;

FIG. 15 is a fragmentary cross-sectional view taken along line XVXV of FIG. 14;

FIG. 16 is a plan view taken along line XVIXVI of FIG. 14, with the band strip being removed and portions of the apparatus broken away;

FIG. 17 is a partial cross-sectional view taken along line XVII-XVII of FIG. 14;

FIG. 18 is a schematic diagram showing the control circuit to be used with any of the above-mentioned detectors, according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION In the following detailed description of the present invention, with respect to the various embodiments and modifications, corresponding structure throughout the various embodiments and modifications will generally be identified with corresponding numbers, with letters to indicate the embodiments and modifications, and in general duplicated structure will not be repeatedly de scribed when shown in more than one embodiment or modification.

FIGS. land 2, respectively show different locations or arrangements for the detector in a rolling mill. FIGS. 3 and 4 show the detector roll of FIG. 1 and the detector roll of FIG. 2. FIGS. 4-17 shown embodiments and variations of the internalstructure for the detector roll that is shown in FIGS. 3 and 4. v

The rolling apparatus of FIG. 1 will detect the profile at 5 of the band plate or strip S, which is being rolled by the final stage roll stand 1 of generally any type of rolling mill. The deflector roll 4 is 'driven to exert tension on the band or strip S, which is being reeled by the take up drum 3 after the strip has been reduced by rolling through the work rolls 2 of the roll stand 1. The apparatus for the detecting the profile of the strip at 5, comprises at detecting roll 6, which is directly contacting or engaging the back side or bottom side of the strip S in combination with a controlled circuit 7 to generate control signals from the detected signals of said detecting roll 6. Output signals Ajfrom the control circuit 7 are transmitted, for example, to a bending device for the work rolls 2 and/or output signals LV are transmitted to the back-up rolls 8 for controlling the profile of the strip S. l i

In the example of a rolling arrangment as shown in FIG- 2, the deflector roller 4 that is shown in FIG. 1 has been removed, and the detector roller 6 of the apparatus according to FIG. 2 for deteeting the profile is used instead of the deflector 4 for exerting the tension on the strip S. The control method, control apparatus, and rolling mill structure may otherwise be identical to that shown in FIG. 1 and already described.

Since the above general arrangements shown in FIGS. 1 and 2, and similar arrangements are well known in the art, further and more detailed description will not be given here.

The detector roll 6 of FIGS. 1 and 2, according to the present invention preferred embodiment is shown in detail with its mounting structure in FIGS 3 and 4, to be described in detail below.

As shown in FIG. 3 and FIG. 4 a stand or housing 10 is fixed or rigid with respect to the floor supporting the rolling mill, which floor is not shown, and a detecting head 11 is movably mounted along the inside walls of the housing 10 by means of mechanisms 12 that will allow the detecting head 11 to be moved upwardly or downwardly as desired with respect to the strip 8. The detecting head 11 or roll in general, comprises amovable rest or support 13 that is generally of boxed construction, a shaft 15 having its opposed ends horizontally fixed in a pair of bearings 14, which bearings 14 are mounted in the vertical direction on the movable rest 13. The movable rest 13 is guided for vertical movement by suitable guide plates or channels mounted on the vertical walls of the housing 10, and cylinders or the like are used to move the opposite ends of the rest 13 upwardly and downwardly. A plurality of individual detectors 16, which have outer cylindrical surfaces that are rotatable with respectto each other, are mounted on the shaft 15, which shaft 15 is fixed to the moving rest 13.

As shown in FIG. 3, a plurality of detectors 16 are mounted adjacent each other along the general detec tor roll 11; each of these detectors is of identical construction and therefore only one will be disclosed and described in detail with respect to FIGS. 5 and 6.

As shown in FIGS. 5 and 6, each of the detectors 16 includes a swinging annular body or inner ring 17, which is mounted on the stationary shaft 15 for swinging movement about an axis parallel to the central axis of the shaft 15, which axes are spaced from each other so that the position of the inner ring 17 is eccentric with respect to the shaft 15. An outer ring 19, which has an external cylindrical surface in contact with the underside of the traveling strip S, is mounted rotatably on the inner ring 17 by a plurality of bearing rollers 18 between the outer surface of the inner ring 17 and the inner surface of the outer ring 19. Transducer means for measuring or detecting force, for example a load cell 20, is disposed between the inner surface of the inner ring 17 and the outer surface of the shaft 15, to detect the forces tending to pivot or swing the inner ring 17 about its pivotal mounting to the shaft 15.

In the outer surface of the shaft 15, a groove, recess, or flat portion 21 or the like is formed to extend the full length of the shaft 15 parallel to the axis of the shaft 15. A long slide plate 22, substantially equal to the length of the shaft 15, has a plurality of such load cells 20, equal in numberto the detector 16, fixedly mounted thereon at even spaces corresponding to the uniform spacing of the detector 16 along the shaft 15. A slightly shallow recess 23 is formed adjacent to the groove 21 for receiving therein electrical wires for carrying the input and output for the load cells a supporter secures these wires 24 to the slide plate 22. Thus, the slide plate 22 may be slid into and out of the groove 21, in the axial direction of the shaft 15, along with the wires 24 and their carrier 25 that will slide into and out of the recess 23, so that the load cells 20 may be moved from the overall detector roll 11 whenever it is necessary to inspect or repair them, without otherwise requiring diassembly of the elements shown in FIGS. 5 and 6.

As shown in FIG. 5, a flat portion 26 is provided on the surface of the shaft 15 and for substantially the entire length of the shaft 15 in parallel with the axial direction of the shaft 15. On the outer surface of the shaft 15, adjacent the flat portion 26, there is formed a generally square recess 27 at regular intervals in the axial direction of the shaft 15. A plurality of bearing blocks 29 are mounted on shaft 15 by means of their projecting bottom portions 29A being received within the cor respondingly shaped recesses 27. The number of bearings 29 is sufficient to provide a bearing 29 on opposite axial sides of each of the inner rings 17, as shown in FIG. 6, with the bearings 29 being secured fixedly in place on the shaft 15 by means of the bolts 28 in accurate positions as determined by the inner engaging guide portions 29A and 27. All of the bearings 29 have axially aligned holes receiving therein needle bearings 31 for rotatably supporting pins 33, to be described hereinafter.

Each of the inner rings 17 is pivotally or swingingly mounted on the shaft 15 by means of a pin 33 extending through a hole in the inner ring 17, which hole is aligned with the previously mentioned holes of the bearings 29. Preferably, the pin 33 non-rotatably receives the inner ring 17 and has its opposite en rotatably mounted by the needle bearings 31 within adjacent bearings 20. Axial shifting of the inner ring 17 is prevented by means of thrust bearings 32 extending between each side of the inner ring 17 around the pin 33 and the adjacent bearings 29. Thus, the opposite ends of the pin 33 that project from the opposite ends of the inner ring 17 will pass through the thrust bearings 32 and be rotatably supported within the bearings 31. By such a construction, the inner ring 17 is supported by the bearings 29 so as to be swingable with the pin 33, which pin 33 has an axis parallel to the axis of the shaft 15.

As shown ,infFlG. 6, the outer surface of the inner ring 17 is provided with a ring shaped projection 271, which is provided with opposite axial facing end shoulders 272. In this manner, the ring shaped projection 271 has its end faces 272 in engagement with the rollers 18, which rollers 18 in turn are received within an annular groove about the inner periphery of the outer ring 19 with corresponding shoulders of the outer ring 19 engaging the outer axial ends of the bearing rollers 18. In this manner, the outer ring 19 is rotatably mounted on the inner ring 17 for rotation about an axis parallel to the axis of the pin 33 and further fixed against any axial movement in the axial direction of the shaft 15. As shown, the annular recess or groove 191 formed within the central portion of the inside surface of the outer ring 19, which as mentioned above receives therein the rollers 18, has a width that is equal, in the axial direction, with the length between the adjacent two rollers 18 and the axial width of the projection 271. Thus, it is seen that the rollers .18 contact the outer surface of the inner ring 17 and the inner surface of the outer ring 19, while they are received within the groove 191 of the outer ring to prevent their axial movement and the axial movement of the outer ring 19, with respect to the inner ring 17 in combination with the annular projection 271.

Further, as previously described, the inner ring 17 is prevented from moving in the axial direction by means of the bearings 19 and the thrust bearings 32, so that the movement of the outer ring 19 in the axial direction is arrested by the annular groove 191 formed on the inside of the outer ring 19, the rollers 18 inserted within the groove 191, the annular projection 27] of the inner ring 17, the thrust bearings 32, and the bearings 29 that are rigidly mounted on the shaft 15.

On the flat portion 26 formed on the periphery of the shaft 15, there are a plurality of attachments 34 for lubricating oil piping. These supports or attachments 34 have aligned holes for receiving therein a pipe 35 that conducts lubricating oil under pressure axially along the area formed by the flat portion 26 of the shaft 15. A plurality of injecting conduits 36 extend radially from the lubricating oil pipe 35, and preferably these radially extending injection conduits 36 are rotatably mounted about the center of the pipe 35. A T-shaped nozzle 37 is provided on the outer extremeity of each of the injecting conduits 36 for discharging lubricating *in engagement with the load cell 20.

The operation of the detecting device for determining theflatness of the band plate S, that'isfor determin irig the profile as mentioned above, will be explained hereinbelow with respect to the apparatus of FIGS.

' f and 6.

oil in a jet toward the roller bearings 18 in the position shown in FIG. 5 and FIG. 6 as the outer ring 19 rotates about the inner ring 17. As shown in FIG. 6, a nozzle 37 is provided axially adjacent each peripheral row if bearing rollers 18. The pipe 35, injecting conduits 36, and T-shaped nozzles 37 may be swung about the axis of the pipe 35 to provide clearance in assembly and disassembly of the apparatus, but during functioning of the apparatus they are in the position as shown in FIGS. 5 and 6.

As shown in FIG. 6, the outer rings 19 are axially arranged very close to eachother on'the shaft 15, in parallel with each other, so that there will only be very small gaps between adjacent outer rings 19, so that the detector roll will not scar the strip which is being moved in the tangential direction of the outer periphery of the outer .rings 19 under the condition of tension acting on the strip S. Axially adjacent annular shallow recesses are formed in the end faces of the outer rings 19, and O-rings 38 having diameters larger than twice the depth of the annular shallow recesses are inserted into these recesses, so that the spaces interior of the outer rings 19 are completely closed and sealed with respect to the outside thereof. With such a construction, the strip S that is in engagement with the outer ring 19 is prevented from polluting the lubricating oil within the interior of the outer rings 19 and further the strip S afterrolling on the outer rings 19 is'not scarred or-otherwise adversely affected thereby.

- In addition to the above construction, it is noted that the ends of the outer rings 19 are about the center portion of the adjacent bearings 29, and the nozzles 37 exto bedisposed atthe end portions of the outer rings 19, all of which will prevent oil leakage to the exterior in amost satisfactory manner.

A plurality of generally radially extending holes or bores 39 are axially and uniformly spaced along the shaft 15, and generally correspond in number and are v radially opposite the inner rings 17. Each hole 39 generally extends from the surface of the shaft to the interior of the shaft 15 in a direction parallel with the direction of force application on the load cell 20. A plunger 41 is xbiased outwardlyby means of a coil spring [40 and slidably extends througha hole4l in a retaining piece within the hole 39. The spring 40 exerts a spring load cell 20 is always able to operate correctly within a proper measuring scope, and the impulse contact of .the load 20 and the inner ring 17 is avoided thereby, because due to this bias the inner ring 17 will always be When the strip or band S is undergoing rolling reduc' tion and traveling in the direction of the arrow f in'engagement withthe surface of the outer rings 19 under considerabletension, the outer rings 19 will be rotated thefri'c tional force induced between the back side tend toward the interior of the outer rings 19 so as not w of the strip S and the surfaces of the outer rings 19. At the same time, the normal component Tn of the tension T acting on the strip S acts on the inner ring 17, through the intermediary of the outer ring 19 and roller bearings 18. Since the inner rings 17 are rotatably connected or swingingly connected to the shaft 15 by means of the pivot pins 33 for rotation about an axis considerably spaced from the line of action for the normal component Tn, the inner rings 17 will be swung about the axis of the pins 33 by the normal component Tn. Namely, the inner ring 17 is rotated with the outer ring 19 by a turning moment comprising the normal component Tn and the distance between the axis of the pins 33 and the line of action of the normal component Tn. When the inner rings 17 are swung or rotated about the axis of their pins 33, each inner surface of each inner ring 17 is pressed into engagement with the corresponding load cell 20 disposed in the recess of the shaft 15, and the normal component Tn of the tension T will be detected by the load cell 20, with the load cell 20 preferably being aligned with the direction of action for the normal component Tn. Namely, the load cell 20 will detect the reaction of the turning moment.

FIG 7, FIG. 8, and FIG. 9 show another embodiment of the detectors 16. Since the embodiment of FIGS. 7-9 does not differ from the embodiment of the detector shown in FIGS. 5 and 6 in principle, only the structural differences between these two embodiments will be set forth in detail, and for further description of similar structure, reference is made to the above detailed 1 description of FIGS. 5 and 6.

Three flat portions 42A, 42B, and 42C are formed on the surface of the shaft 15A at equal angles about the periphery of the shaft and generally for the full axial extent of the shaft 15A. On these flat portions, a load demotor 50 and twosupporting devices 51 are respectively mounted for each of the detectors 16. The detector 50 is similar to the detector shown in FIGS. 5 and 6,and comprises a pivot pin 33A that has its opposite ends rotatably supported in bearings 29A that arefixed to the shaft 15A, with the intermediary of needle bearings 31A. A swinging arm 43 has one end fixed to the pin 33A. A guide ring 45 is rotatably mounted on the swinging arm 43 for engaging the inner surface of the outer ring 19A, with its central portion rotatably supdoes not differ from that. shown in FIGS. 5 and 6 in principle, the same parts or their equivalents have been shown with the same numbers and the suffix A to designatethe second embodiment. The above-mentioned structure is repeated for each one of the outer rings 19A. Two substantially identical supporting devices 51 are provided for each of the outer rings 19A, and they are fixed on the flat portions 428 and 42C, respec: tively. Each of the generally square recesses 52 formed along the axis of'the 15A at equal distances has formed therein arcua te recesses'53 concentric with the center of the respective axes of shafts 57, which shafts 57 are parallel with'thej axis of the shaft 15A. A short beam 55 has a bottom face similar in shape to the arcua radius generally equal to'that of the outer ring 19A, and there is a small gap between the cylindrical face of the beam 55 and the inner surface of the outer ring 19A. The center portion of the beam 55 is hollow or divided into a pair of parts forming a hole 54. A pin 57 extends across the hole 54 between the pair of parts of the beam and is fixed to the beam. A ring 59 that is received within the arcuate recess 53, with a slight gap therebetween, is rotatably mounted on the center portions of the pin 57 by means of roller bearings 58, so that the outer surface of the ring 59 is in rolling engagement with the inner surface of the outer ring 19A.

From the above, it will be seen that each of the outer rings 19a will be rotatably mounted on the shaft 15A by means of the rings 59 and 45, and that the swinging arm 43 corresponds to the inner ring 17 in FIG. and that each ring 45, 59 corresponds to the rollers 18 in FIG. 5. Since the operation is similar to that of the embodiment of FIG. 5, and the structure is otherwise similar where corresponding numerals are used, further description of the structure and operation will be dispensed with.

In the embodiment of FIG. 10, high pressure fluid or high pressure air is used for supporting the outer ring 19A on the shaft 15A. In this embodiment, the outer ring 19A is so made that the high pressure fluid is injected into the very small space between the outer ring 19A and the shaft 15A through a plurality of radially extending injecting holes 61 formed between a high pressure axially extending supply conduit 60 formed in the interior of the shaft 15 in the space between the outer ring 19A and shaft 15A. Thus, the outer ring 19A is floated by this fluid bearing for rotation on the shaft 15, so that the outer ring may be very smoothly rotated. The upper portion that is broken away may correspond indentically to the upper portion of FIG. 7 with respect to the load detector structure 50, and the fluid bearing will further function to preload the detector load cell.

The embodiment of the apparatus as shown in FIG. 11 will provide a preload on the load cell 20 (not shown) by use of high pressure fluid. In this embodiment, the structure of the outer ring 19, the bearings 18, and the inner ring 17 may be substantially the same as that of FIG. 5, with the broken away upper portion of FIG. 11 corresponding identically to the upper portion of the structure shown in FIG. 5. Thus, the apparatus of FIG. 11 will inject high pressure fluid in the small space between the inner ring 17 and the shaft 15 through a single injecting hole 62 radially extending from a high pressure fluid supplying hole or conduit 62 formed within the interior of the shaft 15A, so that small displacement relative to the axis of the shaft 15 is given to the ring 17 to exert a preload on the load cell 20. Thus, it is effectively seen that the preload structure 62, 63 of FIG. 11 may be substituted for the preload structure 39, 40, 41 of FIG. 5, or elsewhere in the embodiments.

A further embodiment of the profile detecting apparatus is disclosed in FIGS. 12 and 13.

In FIG. 12, the shaft 15B is stationarily mounted with respect to the housing through bearing 14, the moving rest 13 and the mechanism 12 for moving the rest 13 upwardly and downwardly, as previously described with respect to FIG. 3. The inner ring 17B is rotatably mounted on the stationary shaft 158 by means of a plurality of bearing rollers 66 and a guide groove receiving therein the rollers 66 and formed between opposed grooves of the shaft 15B and inner ring 17B. The inner ring 178 has an outer surface eccentric with respect to its inner surface forming the groove 67 and further eccentric with respect to the shaft 15B. The outer ring 198, which engages with the strip S and on which the component of tension acts, is mounted on the inner ring 17B by means of a plurality of rollers 1813. Thus, the inner ring 178 is mounted for concentric rotation about the shaft 158, and the outer ring 198 is mounted for rotation about the outer surface of the inner ring 17B, which is eccentric with respect to the center of the shaft 15B. In the side portion of the inner ring 178, a stopper plate 64 is rigidly secured for mounting the measuring device or load cell 208 by means of bolts 65 that extend into the inner ring 178. The load cell 20B engages with a recess formed on the adjacent side portion of the shaft 158.

Since the eccentric distance between the center, on line BB, of the shaft 15B and the center of the outer surface of the inner ring 178 on line AA is the distance 1 and further since the normal component is T of the tension T in the strip S, then it is seen that the turning moment 1 Tn is induced and, its reaction will act directly on the load cell 208. Therefore, the stress in a portion of the strip engaged by the particular detecting ring 16 is detected or measured by the corresponding load cell 208.

It is understood that in the embodiment of FIG. 12, that only one of a plurality of identical detecting ring 16 is disclosed.

FIG. 13 shows a variation of the embodiment of FIG. 12, that is generally the same except for the mounting of the load cell 20B. Thus, in the variation of FIG. 13, the distance 1;, between the center of the shaft 15B and the point at which the load cell 208 acts is shorter than the corresponding distance 1 in FIG. 12. Therefore, it is possible to exert a stronger maximum force in one variation as compared with the other variation on the load cell white producing a stable output signal from the load cell.

A further embodiment of one detecting ring is shown in FIGS. 14-17.

The shaft 15C of FIG. 14 corresponds to the shaft 15 in FIG. 5. In the upper portion of the shaft 15C, there if formed a recess 151 extending along the axis of the shaft 15C. A projection 291 on the lower portion of a bearing 29C is slidably inserted in the recess 151, to locate precisely the bearing, which is fixed to the shaft 15C by bolt 68. The bearing 29C is one of a plurality of paired bearings 29C as shown in FIG. 17, with a shaft 33C supported between adjacent pairs of bearings 29C by means of the needle bearings 31C. A holder 17C, which corresponds to the inner ring 17 in FIG. .5, is secured to the center portion of the shaft 33C, and thrust bearings 32C are provided between the opposed sides of the holder 17C and each bearing 29C. Thereby, the holder 17C is prevented from displacement in the axial direction of the shaft 33C and is swung or rotated about the axis of the shaft 33C. The inside of the holder 17C is arcuately shaped and surrounds the shaft 15C in the same way as shown with respect to the holder '17 in FIG. 5. Roller or ball bearings 69 are provided at both outer ring 19C is rotated in contact with the strip S.

Thereby, the normal component Tn of the tension T of the strip 5 is transmitted to the holder ,17C through the rotatably mounted outer ring 19C to swing or turn the holder 17C about the axis of the shaft 33C. The normal component T, of the tension T and the distance between the vertical lines passing through the axis of the shaft 33C and the center of the bearing mounted in the center of the holder 17C induce a turning moment about the shaft 33C.

The pin 70, which has small diameter portions at its opposite ends, is fixed to the holder 17C in its central portion as shown in FIG. 15. The bearing 69 is fixed to each small diameter end portion of the pin 70 by means of stop rings 70. The outer ring 19C has a recess annularly formed along its inner periphery, which recess rcceives therein the bearings 69 and serves to prevent axial displacement of the outer ring 19C. Thereby, the outer ring 19C is only permitted to rotate about its axis. The width of the outer ring 19C is determined by the number of points which are detected over the width of the strip S, as in the other embodiments, and is a little longer than the length of the pin 70 or the shaft 33C or the distance between the outside of the pair of bearings 29C, so that it is possible to arrange a plurality of the outer rings 19C very closely adjacent to each other in the axial direction.

A recess 21 for inserting a slide plate 22C is formed on the upper portion of the shaft C along its axial direction, with the slide plate 22C carrying thereon a plurality of load cells C to provide the means for measuring the force. Further, the slide 22C carries therewith lead wires 24C for the electrical input and output of the various load cells 20C, much in the manner previously described with respect to the previous embodiment. When the slide plate 22C is inserted by sliding it in at the predetermined place, the force sensing portions of the load cells 20C contact the central portion of the holder 17C. As previously mentioned, each of the detectors is constructed, so that it is possible to convert the normal component Tn of the tension T of the strip S into turning moments or swinging moments about the shaft 33C of the holder 17C through the outer ring 19C and to detect its reaction through the load cell 20C.

A plurality of such detectors 16, as shown in FIGS. 14-16, are identical and arranged evenly along the width direction of the strip S. A plurality of groups comprising the bearings 29C, the holder 17C and the outer ring 19C are provided on the common shaft 15C fixed to the housing, through the bearing 14, the moving rest 13 and the mechanism for providing the up and down movement as shown in FIG. 3. The holding portions (the holder 17C, the bearing 29C, etc.) of the outer ring 19C are contained in the outer ring 19C, so that a plurality of the outer rings 19C are able to be arranged very closely adjacent to each other. Grooves are provided in the adjacent end faces of the outer rings 19C for receiving therein the O-rings 38C, which will prevent leakage of the lubricating oil from the interior of the outer ring 19C and further prevent outside contamination from reaching the interior. The load cells 20C are each attached on the slide plate 22C at the position corresponding to each of the holders 17C, respectively. Thereby, it is possible to remove a plurality of the load cells by drawing out the slide plate 22C axially along the shaft 15C, without disassembling the holder 17C and its supporting structure. Lubricating oil supplying conduits 35C, for lubricating the interior of the outer ring 19C, are arranged along the shaft 15C.

The branched conduits 13C for providing lubricating oil to the sides of each of the bearings 69 are branched from the conduits 35C. Further, the conduit 35c is constructed so as to be able to turn or rotate between its full line position during operation of the device and the dotted line position that is used for assembly and disassembly, are shown particularly in FIG. 14.

In assembly of the detector mentioned above, after the bearings 29C, the shaft 33C, the needle bearings 31C, the thrust bearings 32C, the holders 17C, the shaft 70, the bearing 69, and the outer rings 19C, the projection 291 of the bearing 29C of these assemblies is inserted in the recess 151 of the shaft 17C and fixed by'the bolts 68 at the predetermined positions. After the same'operations as above mentioned are repeated several times, the slide plate 22C on which the load cells 20C and the lead wires 24C are attached is inserted in the recess 21 of the shaft 15C at the predetermined position. The detectors 16C are thereby arranged over the full length of the strip S.

Operation of all of the embodiments for the detectors has been described along with their structure and applies equally well as between the embodiments for simi lar structure.

FIG. 18 coordinates the above-mentioned structure with the schematic control circuit for the profile detecting apparatus of the present invention. The control circuit comprises a comparatory indicating circuit 101 for comparing output signals from the various load cells 20 that are respectively disposed within the detector 16 with reference signals and for indicating the difference between the load signals and the reference signals, and further comprises a reference signal generating circuit 102.

The comparatory-indicating circuit 101, comprises a plurality of amplifiers 103, for respectively receiving and amplifying the electrical signal outputs from the respective load cells 20, which signals are correlated to theflforce exerted on the load cells. A summing device or adder 104L receives the outputs from the left hand group of amplifiers 103, and a summing device or adder 104R receives and sums up the outputs from the right hand ones of the amplifiers 103; an operational amplifier 105 receives the summation signal from the adder 104L and the summation signal from the adder 104R for differentially comparing the two signals from 104L and 104R to produce a differential signal LV, and for summing these two signals from 104L and 104R to produce a summation signal T. The use of these two signals T, LV will be mentioned hereafter.

Also, the outputs from the various amplifiers 103 are fed to respective comparators 106, for comparing the outputs of the respective amplifiers 103 with a reference signal Ta, which comparators will determine the difference between the two input signals and feed such difference respectively to a plurality of indicating meters 107, for indicating the outputs of the comparators 106 and additionally transferring the outputs of the comparators 106 respectively to output lines (JA through J where they are fed to a known type of operating mechanism for eliminating the deviation from flatness of the strip, which known type of operat ing mechanism is not disclosed since it may be of any known type, for example of the roll bending type. Further, there are a plurality of comparators (four being shown) on the left hand side of the circuit 106L and a plurality of similar comparators on the right hand side of the circuit 106R. As shown, switches 118 may directly feed the outputs from the amplifiers 103 to the comparators 106, as shown for the outer three amplifiers 103 on each side, or the switches 118 may be in the position shown for the fourth from the end switch on each side to transmit the outputs from the amplifiers 103 first to the comparators 106L, 106R, where they are compared with a reference signal T,., so that the difference between these two signals will be thereafter sent from the comparators 106L and 106R to their respective comparators 106.

The reference signal generating circuit 103 includes a switching means 108 and a reference signal generator 109. The reference signal generator 109 includes a calculator or computer 110, a selector 111, and a presetter 119. The presetter 119 presets the signal B that corresponds to the width of the strip S, which signal B is transmitted to the selector 111 for selecting the contacts of the switching means 108 corresponding to, for example, the detector covering area e of the strip S at its edge; this is accomplished by adjusting the slid actuator 13 to the left or to the right for closing the corresponding switches of the switching means 108 and thereby operating the switches 1 18 so that only the detector 16 that engages the edge of the strip S in the area e will be connected by the switch 118 through its respective comparator 106L or 106R to the respective comparator 106. The computer 110 will calculate or compute the magnitudes of the signals Ta and Te, which reference signals relate to tensions both at the edges of the strip and at the center portions of the strip, based on the outputs T of the operational amplifier 105 and the signal 8 from the presetter 118, as will be explained more fully hereafter.

The reference signal generators will generate a number of signals corresponding to the number of detectors 16, for adjusting or comparing the output signals from the respective detectors.

At the input side of the control circuit described above, there are provided relay contactors 112, which are closed only in the presence of an input signal, so that the corresponding indicator meters 107 can operate only at the suitable timings. As apparent from FIG. 18, the relay contactors 112 that are disposed on the input side of the indicating means 107 are closed by signals from the switching means 108, which are generated at the same time when the plurality of reference signal generators generate the reference signals. As previously mentioned, the plurality of selector switches 118 that are disposed at the output side of the plurality of amplifiers 103 are actuated by the output signal R2 from the switching means 108 so that the amplifiers 103 associated with the edge of the strip S will be connected with the respective comparators 106L and 106R by operation of the selector switches.

The operation of the control circuit together with the operation of the specific detecting means will be set forth for detecting the profile of a strip S, which has unevenness on its surface (when relaxed), even though under tension produced during rolling.

First, the control system for the measurement method of the present invention will be set forth.

In the embodiment according to the present invention, a system is employed in which an adjusting and controlling signal is generated by comparison with the measured results obtained by measuring the plate unevenness with the detectors arranged symmetrically with respect to the central line X-X of the strip width. According to this system, the position of the uneveness on the surface of the strip is most easily detected and, in addition, the profile control of the strip can be performed most precisely and readily.

After rolling of the strip has been started, with the strip passing through the working rolls of the roll stand, the detecting head 11 is kept down sufficientl, by the lifting mechanism 12 at the time when the tip of the strip is drawn from the final stage stand of the mill and then passed over the detectors 16 to be reeled on the drum 3. After the tension has been applied by the drum 3 to the stripS such that the tension has reached a stable state (the stable state of the tension, for example, by detection of the change of load current of the motor used for the tension producing mechanism, particularly the motor used to drive the drum 3, or any other suitable manner),fthen, the detecting heads 11 are moved upwardly by the power mechanism 12 to a predetermined position, where the detectors 16 are in contact with compression against the back or under-face of the strip S at a predetermined pressure, so as to produce the previously mentioned perpendicular component of tension force Tn. As a consequence, the outer rings 19 are rotated by friction due to the direct contact between the back face of the strip s and the cylindrical peripheral faces of the outer rings 19. With such an operation, the ideal desired state is such that the surface of the strip S being rolled should be completely flat and even. even if the tension were removed, as shown by the horizontal line 114 in FIG. 18 in the graph used for purposes of illustration and positioned immediately above the actual sheet in the drawing. However, the surface is not even in the actual case of rolling and has an unevenness, particularly in the relaxed state, as shown in an exaggerated manner by the curve 115. Therefore, the magnitudes of the output signals from the various load cells 20 that are disposed within the individual detectors 16 are proportional to the uneven ness ratio of the curve 115 to the horizontal line 114, and these unevenness signals correspondingly have positive or negative polarity, respectively. These output signals should, as will be described later, be modified by comparison with the reference tension signals to thereby indicate the actual tension distribution, which as discussed earlier corresponds with the actual evenness distribution or profile. In this case where the whole width of the detector heads, which is constituted by all of the detector 16, is larger than the strip width B to be measured, the output signals of the detectors 16E that are in contact with the slide faces or edges of the strip have to be treated separately from those of the other detectors.

As stated above, in the present invention, after the two regions divided by the central line XX along the width of the strip are separately measured, the measured results are compared with each other.

After the respective output signals generated by the load cells 20 that are disposed within the detector 16 are amplified by the amplifiers 103, which are equal in number with the number of detectors, these amplified signals are supplied respectively to the comparators 106, and at the same time, the detector signals with respect to the left hand portion of the central line X-X of the strip are supplied to the adder 104L and the de tector signals with respect to the right hand portion of the central line XX are supplied to the adder 104R.

Therefore, the output from the adder l04L is a signal corresponding to the mean value of tension on the surface of the left hand of the central line XX. Further, the output signal from the adder 104R is a signal corresponding to the mean value of tension on the surface of the right hand portion of the central line X-X. Next, the output signals from the adders 104L and 104R are supplied to the operational amplifier 105 for summing to produce a summation detecting signal T. Further, the output signals from the adders 104L and 104R are subtracted so as to produce a variation signal LV. The signal LV is used for operating suitable mechanisms controlling the pressure distribution across the working rolls.

The output summation signal T is supplied to the reference value computer 110 in the reference signal generating circuit 102. At the same time, the width value B of the strip is introduced by the presetter 1 19 into the computer 1 10, where computation of the reference values Te and Ta is carried out in order to modify the outputs of the detectors 162 and 16a, which are arranged respectively at and between the edges of the strip or band S.

When the width of the strip S contacting the outer rings 19 of the detectors arranged at the edges of the strip S is e and the width of the strip contacting with the outer rings arranged between the outermost rings 19 be computed for the reference signals as indicated above.

The signal B that corresponds 'to the strip width B is supplied to the selector 1 11, wherein both side position deciding signals are generated so that the end position signal operates the switch means 108 as has been previously described. That is, when the two end position deciding signal is generated from the selector 1 11, the contacts 1081 of the switching means 108 that corre spond to the sides of the strip are closed as indicated in FIG. 18."In this manner, the signals R and R are supplied to the relay contactors or switches 1 l2 and the selectorswitches 118, respectively, in order to close therelay contactors 112 and connect the amplifiers 103 to the comparators 106L and 106R.

;On the other hand, the signal B corresponding to the U strip width. is also supplied to the reference value com- I puter 110, and the modifying reference values Ta and .Te are'computed as mentioned above with the addition of the summation output signal T from the operating amplifiers I05 and the signal from the presetter 119 J according to the previously mentioned formulas. As a result, the reference tension signals Te andTaare suppliedlto the respective comparators 106, 106R, 1061., whereby comparison of the output signals from the load cells with the reference tension signals Te and Ta is carried out in the respective comparators and the differential outputs areindicated in the respective. indicating meters 107. Since the reference scale line 1 16 is formedon the meter board, thetension distribution alon'gthe direction of the width of the strip S is indicate'd'elear'ly by the visual indicators 117. At the same time, the differential outputs 1A through JA from the respective indicating meters, is supplied to the operating device for controlling the profile (not shown in FIG. 18), which may be of any known type, for example of the type wherein the working rolls are bent.

Since much of the operation has been disclosed along with the structure, further description of the operation will not be given in detail. v

While various embodiments and modifications with variations have been shown and described specifically according to the present invention, with the details being important, further modifications, variations and embodiments of the present invention are contemplated according to the broader aspects of the present invention, all as determined by the spirit and scope of the following claims. I

What is claimed is: 1. Apparatus for detecting the relaxed flatness profile of a traveling band plate moving under tension along a predetermined path, comprising: a support extending transversely of said band plate path of travel; a plurality of detector members adjacent each other in the transverse direction and being movably mounted by said support member at predetermined distances apart; said detector members including means mounting them for angular movement relative to said support member by a tension moment exerted by a component of the band plate tension that is generally perpendicular to the path of travel at the respective points of engagement; each of said detector members having an outer ring surrounding part of said support and part of said detector member, and being freely' rotatably mounted for engaging the traveling band plate; and transducer means between each of said detector members and said support for detecting a force of a reaction moment equal to the tension moment on the movable detector members in each of said outer rings, and producing an output signal correlated to the detected force and'thus correlated to the band plate tension at the point of detector engagement. I

2..The apparatus of claim 1, including a signal control circuit comprising means for summing the output signals from said transducer means and producing a reference signal from the signal summation; and said circuit further including means for comparing each of said transducer signals with said reference signal.

3. The apparatus of claim 1, wherein each of said detector members is swingably mounted on said support for pivoting movement about an axis spaced from a line of action of said component of the band plate tension; and said force detecting transducer means being fixably mounted on saidsupport member at a predetermined distance from said axis to create therewith the reaction moment.

4. The apparatus of claim 3, wherein each of said detector members is rotatably mounted about an axis and further includes a plurality of bearings contacting an 8. Apparatus for detecting the relaxed flatness profile of a traveling band plate moving under tension along a predetermined path, comprising: a support extending transversely of said band plate path of travel; a plurality of detector members adjacent each other in the transverse direction and being movably mounted by said support member at predetermined distances apart; said detector members including means mounting them for movement relative to said support member by a tension moment exerted by a component of the band plate tension that is generally perpendicular to the path of travel at the respective points of engagement; each of said detector members having an outer ring freely rotatably mounted for engaging the traveling band plate; transducer means between each of said detector members and said support for detecting a force of a reaction moment equal to the tension moment on the movable detector members, and producing an output signal correlated to the detected force and thus correlated to the band plate tension at the point of detector engagement; and a plurality of separate bearings at equal angular spacings around the axis of rotation of said outer ring for rotatably supporting said outer ring on the remaining structure of said detector member.

9. The apparatus of claim 3, wherein said support is mounted for general reciprocating movement generally perpendicularly toward and away from said traveling band path; and including power means for moving said support toward and away from said traveling band plate along its path of reciprocation.

10. Apparatus for detecting the relaxed flatness profile of a traveling band plate moving under tension along a predetermined path, comprising: a support extending transversely of said band plate path of travel; a plurality of detector members adjacent each other in the transverse direction and being movably mounted by said support member at predetermined distances apart; said detector members including means mounting them for movement relative to said support member by a tension moment exerted by a component of the band plate tension that is generally perpendicular to the path of travel at the respective points of engagement; each of said detector members having an outer ring freely rotatably mounted for engaging the traveling band plate; transducer means between each of said detector members and said support for detecting a force of a reaction moment equal to the tension moment on the movable detector members, and producing an output signal correlated to the detected force and thus correlated to the band plate tension at the point of detector engagement; and three separate bearings rotatably mounting said outer ring and being relatively fixed with respect to the remaining structure of said detector members.

11. Apparatus for detecting the relaxed flatness profile of a traveling band plate moving under tension along a predetermined path, comprising: a support extransducer means between each of said detector members and said support for detecting a force of a reaction moment equal to the tension 1Tb ment on the movable detector members, and producing an output signal correlated to the detected force and thus correlated to the band plate tension at the point. of detector engagement; a slide plate having mounted thereon each of said detector transducers; and means for mounting said slide plate on said support for withdrawal as a unit without disassembly of other components of said detector member.

12. The apparatus of claim 11, wherein each of said detector transducers is a load cell producing an electrical output signal, and further having electrical wires mounted on said slide plate leading to and from each of said load cells.

13. Apparatus for detecting the relaxed flatness profile across the transverse width of a band traveling under tension in the direction of its length comprising: a plurality of transversely adjacent individual detectors extending across the entire width of the traveling band; each of said detectors having an outer cylindrical surface of a common diameter for engaging one surface of the band; a common generally stationary support member extending transversely of said band and internally of said cylindrical surfaces; means for mounting all of said detectors on said common support member with their cylindrical surfaces engaging said traveling band to deflect the traveling band from its path of travel and produce a band tension component of force generally perpendicular to the tangent point of contact between said band and cylindrical surfaces for each of said detectors; each of said detectors having an inner movable force transferring member pivotally mounted about an axis on said stationary support member; each of said detectors having an outer ring defining the respective cylindrical surface, and being freely and independently rotatable about a common axis concentric with said outer cylindrical surface; each of said detectors having means transferring said tension component force from said outer ring to said inner movable force transmitting member along a line of action spaced from said inner member pivot axis to thereby produce a moment; each of said detectors having transducer means spaced from said inner member pivot axis and being mounted between said stationary support member and inner member; each of said transducer means producing a reaction force on said inner member spaced from said inner member pivot axis to produce a moment opposite to and counteracting said tension component moment;

each of said transducer means producing an output signal proportional to its reaction force on said inner member, which in turn is correlated to the tension cornponent and band tension at the area of engagement between its detector and the traveling band.

ment of said outer rings and their cylindrical surfaces; and sealing means between adjacent axial end faces of said outer rings within said clearance gaps forming a fluid tight chamber interiorally of said outer rings con taining therein said stationary support member, all of said axes, said transducer means, and said inner member. i

15. The apparatus of claim 14, including antifriction bearings for the rotation of said outer rings and the pivoting of said inner members, and means for injecting a jet of lubricating oil against each of said bearings within said fluid tight chamber.

16. The apparatus of claim 13, including an axial channel in said stationary support member; a slide member guidingly received within said channel and being withdrawable only axially from the area within said outer rings; said slide member carrying thereon each of said transducer means; a plurality of electrical lead wires mounted on said slide for conducting electrical current to and from said individual transducer means.

17. The apparatus of claim 13, wherein each of said outer rings has an inner annular bearing surface concentric with its outer cylindrical surface; said inner member is a ring having an outer cylindrical bearing surface concentric with said outer ring inner annular bearing surface; a plurality of antifriction roller means between said outer ring inner bearing surface and said inner member ring outer bearing surface forming the rotatable mounting for said outer ring; and said pivot axis for said inner member ring being parallel to and transversely spaced from said axis of rotation for said outer ring.

18. The apparatus of claim 17, including an annular inner bearing surface on said inner ring and complementary annular outer bearing surface on said stationary support member; a plurality of antifriction roller means between said inner bearing surface and said stationary support member outer bearing surface; said inner ring inner bearing surface and said stationary member outer bearing surface being concentric with respect to an axis parallel to and spaced transversely from the axis of rotation for said outer ring.

19. The apparatus of claim 13, including means generally diametrically opposed, with respect to the axis of rotation of said outer ring, to said tangential point of engagement for exerting a biasing force between said stationary support member and said inner urging said inner member about its pivot axis into said transducer means to prevent impulse loading.

20. The apparatus of claim 19, wherein said inner member is a ring within said outer ring and surrounding said stationary support member; and said biasing means is a fluid jet from said stationary support member against the inner surface of said inner ring.

21. The apparatus f claim 19, wherein said inner member is a ring within said outer ring and surrounding said stationary support member; and said biasing means is a spring urged plunger mounted within said stationary support member and bearing against said inner ring.

22. The apparatus of claim 13, wherein each of said det'ector outer rings has an inner annular bearing surface; said stationary support member having a partial annular outer bearing surface extending over more than 180 degrees of and closely adjacent the outer ring inner bearing surface to form therebetween a narrow radial gap; and means for injecting high pressure fluid within said narrow gap to form a fluid bearing between said stationary support member and said outer ring; said inner member, pivot axis for said inner member and transducer means being mounted between said stationary support member and said outer ring within the remaining annular portion of said stationary support member not having an outer annular bearing surface.

23. The device of claim 13, wherein each of said detector outer rings has an inner annular bearing surface concentric with said outer cylindrical surface; said inner member being arcuate and extending over more than degrees of the outer ring, with a pivotal bearing to said support member being between its terminal ends; a single roller bearing on each terminal end of said inner member in engagement with the inner bearing surface of said outer ring, and a single roller bearing mounted on the central portion of said arcuate inner member and being in engagement with the inner bearing surface of said outer ring; the pivot bearing of said arcuate inner member being between said central roller bearing and one of said terminal end roller bearings.

24. The apparatus of claim 13, wherein each said detector member outer rings has an inner annular bearing surface concentric with said outer cylindrical surface; said inner member being an arm having one end pivotally mounted to said support member, a single antifriction bearing on its central portion in engagement with the internal bearing surface of said outer ring, and a force transmitting terminal end at the opposite end from said pivotal bearing in engagement with said transducer means; further including two additional single roller bearings fixedly mounted on said support member in rolling engagement with the inner bearing surface of said outer ring; and said three roller bearings for each of said detectors being equally spaced around the inner periphery of said outer ring.

25. The apparatus of claim 13, wherein each of said transducer means produces an output electrical control signal, and in combination with a control circuit, comprising: means for summing all of the electrical signals from said transducer means and producing therefrom a first reference signal and a second reference signal such that the ratio between the first reference signal and the second reference signal is equal to the ratio between the transverse width of a detector outer cylindrical surface and the transverse width of the plate edge in engagement with a detector outer cylindrical surface; means for individually comparing the transducer signals from the detectors that are in full transverse band engagement with said first reference signal to produce a corresponding plurality of output signals each proportional to the tension and thus flatness of the middle of the band at its corresponding measuring point; and means for individually comparing the transducer signals from the detectors that are partially engaging the edge of the band with said second reference signal to produce outputs correlated to the tension in the band edges and thus correlated to the flatness of the band edges.

26. The apparatus of claim 13, in combination with a rolling mill comprising: a roll stand including opposed working rolls and back up rolls for the rolling reduction of the traveling band; said detectors being located to engage the band as it emerges from the working rolls; circuit means for processing the individual transducer output signals to produce corresponding plate flatness error signals; and means responsive to said flatness error signals for changing the contour of said working rolls to reduce the plate flatness error signals.

27. A method for detecting the relaxed flatness profile across the transverse width of a band traveling under tension in the direction of its length, comprising the steps of: engaging one surface of the band plate throughout substantially its entire transverse width with a plurality ofindividual detectors having outer cylindrical surfaces transversely aligned with each other and of a common diameter to deflect the traveling band from its path of travel and produce a band tension component of force generally perpendicular to the tangent point of contact beween the band and the cylindrical surfaces of the detectors; freely rotating all of the outer cylindrical surfaces of the detectors independently of each other; supporting each of said frecly rotatable detector cylindrical surfaces for pivotal movement about an axis spaced from the generally perpendicular to the duce an indication of relaxed band profile. 

1. Apparatus for detecting the relaxed flatness profile of a traveling band plate moving under tension along a predetermined path, comprising: a support extending transversely of said band plate path of travel; a plurality of detector members adjacent each other in the transverse direction and being movably mounted by said support member at predetermined distances apart; said detector members including means mounting them for angular movement relative to said support member by a tension moment exerted by a component of the band plate tension that is generally perpendicular to the path of travel At the respective points of engagement; each of said detector members having an outer ring surrounding part of said support and part of said detector member, and being freely rotatably mounted for engaging the traveling band plate; and transducer means between each of said detector members and said support for detecting a force of a reaction moment equal to the tension moment on the movable detector members in each of said outer rings, and producing an output signal correlated to the detected force and thus correlated to the band plate tension at the point of detector engagement.
 2. The apparatus of claim 1, including a signal control circuit comprising means for summing the output signals from said transducer means and producing a reference signal from the signal summation; and said circuit further including means for comparing each of said transducer signals with said reference signal.
 3. The apparatus of claim 1, wherein each of said detector members is swingably mounted on said support for pivoting movement about an axis spaced from a line of action of said component of the band plate tension; and said force detecting transducer means being fixably mounted on said support member at a predetermined distance from said axis to create therewith the reaction moment.
 4. The apparatus of claim 3, wherein each of said detector members is rotatably mounted about an axis and further includes a plurality of bearings contacting an innerface of said outer ring.
 5. The apparatus of claim 3, wherein each of said detector members is pivotably connected with said support member by shaft and bearing means at said axis.
 6. The apparatus of claim 3, wherein said shaft and bearing means comprises a shaft and two bearings therefor per each of said detector members.
 7. The apparatus of claim 1, including preload means for biasing each of said detector member against its said transducer means with a predetermined force, to prevent impact loading.
 8. Apparatus for detecting the relaxed flatness profile of a traveling band plate moving under tension along a predetermined path, comprising: a support extending transversely of said band plate path of travel; a plurality of detector members adjacent each other in the transverse direction and being movably mounted by said support member at predetermined distances apart; said detector members including means mounting them for movement relative to said support member by a tension moment exerted by a component of the band plate tension that is generally perpendicular to the path of travel at the respective points of engagement; each of said detector members having an outer ring freely rotatably mounted for engaging the traveling band plate; transducer means between each of said detector members and said support for detecting a force of a reaction moment equal to the tension moment on the movable detector members, and producing an output signal correlated to the detected force and thus correlated to the band plate tension at the point of detector engagement; and a plurality of separate bearings at equal angular spacings around the axis of rotation of said outer ring for rotatably supporting said outer ring on the remaining structure of said detector member.
 9. The apparatus of claim 3, wherein said support is mounted for general reciprocating movement generally perpendicularly toward and away from said traveling band path; and including power means for moving said support toward and away from said traveling band plate along its path of reciprocation.
 10. Apparatus for detecting the relaxed flatness profile of a traveling band plate moving under tension along a predetermined path, comprising: a support extending transversely of said band plate path of travel; a plurality of detector members adjacent each other in the transverse direction and being movably mounted by said support member at predetermined distances apart; said detector members including means mounting them for movement relative to said support member by a tension moMent exerted by a component of the band plate tension that is generally perpendicular to the path of travel at the respective points of engagement; each of said detector members having an outer ring freely rotatably mounted for engaging the traveling band plate; transducer means between each of said detector members and said support for detecting a force of a reaction moment equal to the tension moment on the movable detector members, and producing an output signal correlated to the detected force and thus correlated to the band plate tension at the point of detector engagement; and three separate bearings rotatably mounting said outer ring and being relatively fixed with respect to the remaining structure of said detector members.
 11. Apparatus for detecting the relaxed flatness profile of a traveling band plate moving under tension along a predetermined path, comprising: a support extending transversely of said band plate path of travel; a plurality of detector members adjacent each other in the transverse direction and being movable mounted by said support member at predetermined distances apart; said detector members including means mounting them for movement relative to said support member by a tension moment exerted by a component of the band plate tension that is generally perpendicular to the path of travel at the respective points of engagement; each of said detector members having an outer ring freely rotatably mounted for engaging the traveling band plate; transducer means between each of said detector members and said support for detecting a force of a reaction moment equal to the tension moment on the movable detector members, and producing an output signal correlated to the detected force and thus correlated to the band plate tension at the point of detector engagement; a slide plate having mounted thereon each of said detector transducers; and means for mounting said slide plate on said support for withdrawal as a unit without disassembly of other components of said detector member.
 12. The apparatus of claim 11, wherein each of said detector transducers is a load cell producing an electrical output signal, and further having electrical wires mounted on said slide plate leading to and from each of said load cells.
 13. Apparatus for detecting the relaxed flatness profile across the transverse width of a band traveling under tension in the direction of its length comprising: a plurality of transversely adjacent individual detectors extending across the entire width of the traveling band; each of said detectors having an outer cylindrical surface of a common diameter for engaging one surface of the band; a common generally stationary support member extending transversely of said band and internally of said cylindrical surfaces; means for mounting all of said detectors on said common support member with their cylindrical surfaces engaging said traveling band to deflect the traveling band from its path of travel and produce a band tension component of force generally perpendicular to the tangent point of contact between said band and cylindrical surfaces for each of said detectors; each of said detectors having an inner movable force transferring member pivotally mounted about an axis on said stationary support member; each of said detectors having an outer ring defining the respective cylindrical surface, and being freely and independently rotatable about a common axis concentric with said outer cylindrical surface; each of said detectors having means transferring said tension component force from said outer ring to said inner movable force transmitting member along a line of action spaced from said inner member pivot axis to thereby produce a moment; each of said detectors having transducer means spaced from said inner member pivot axis and being mounted between said stationary support member and inner member; each of said transducer means producing a reaction force on said inner member spaced from said inner member pivot axis to produce a moment opposite to anD counteracting said tension component moment; each of said transducer means producing an output signal proportional to its reaction force on said inner member, which in turn is correlated to the tension component and band tension at the area of engagement between its detector and the traveling band.
 14. The apparatus of claim 13, wherein said outer rings are closely spaced adjacent each other across the entire width of said band with only small clearance gaps between their cylindrical surfaces; each of said detector means having means for preventing axial displacement of said outer rings and their cylindrical surfaces; and sealing means between adjacent axial end faces of said outer rings within said clearance gaps forming a fluid tight chamber interiorally of said outer rings containing therein said stationary support member, all of said axes, said transducer means, and said inner member.
 15. The apparatus of claim 14, including antifriction bearings for the rotation of said outer rings and the pivoting of said inner members, and means for injecting a jet of lubricating oil against each of said bearings within said fluid tight chamber.
 16. The apparatus of claim 13, including an axial channel in said stationary support member; a slide member guidingly received within said channel and being withdrawable only axially from the area within said outer rings; said slide member carrying thereon each of said transducer means; a plurality of electrical lead wires mounted on said slide for conducting electrical current to and from said individual transducer means.
 17. The apparatus of claim 13, wherein each of said outer rings has an inner annular bearing surface concentric with its outer cylindrical surface; said inner member is a ring having an outer cylindrical bearing surface concentric with said outer ring inner annular bearing surface; a plurality of antifriction roller means between said outer ring inner bearing surface and said inner member ring outer bearing surface forming the rotatable mounting for said outer ring; and said pivot axis for said inner member ring being parallel to and transversely spaced from said axis of rotation for said outer ring.
 18. The apparatus of claim 17, including an annular inner bearing surface on said inner ring and complementary annular outer bearing surface on said stationary support member; a plurality of antifriction roller means between said inner bearing surface and said stationary support member outer bearing surface; said inner ring inner bearing surface and said stationary member outer bearing surface being concentric with respect to an axis parallel to and spaced transversely from the axis of rotation for said outer ring.
 19. The apparatus of claim 13, including means generally diametrically opposed, with respect to the axis of rotation of said outer ring, to said tangential point of engagement for exerting a biasing force between said stationary support member and said inner urging said inner member about its pivot axis into said transducer means to prevent impulse loading.
 20. The apparatus of claim 19, wherein said inner member is a ring within said outer ring and surrounding said stationary support member; and said biasing means is a fluid jet from said stationary support member against the inner surface of said inner ring.
 21. The apparatus fo claim 19, wherein said inner member is a ring within said outer ring and surrounding said stationary support member; and said biasing means is a spring urged plunger mounted within said stationary support member and bearing against said inner ring.
 22. The apparatus of claim 13, wherein each of said detector outer rings has an inner annular bearing surface; said stationary support member having a partial annular outer bearing surface extending over more than 180 degrees of and closely adjacent the outer ring inner bearing surface to form therebetween a narrow radial gap; and means for injecting high pressure fluid within said narrow gap to form a fluid bearing beTween said stationary support member and said outer ring; said inner member, pivot axis for said inner member and transducer means being mounted between said stationary support member and said outer ring within the remaining annular portion of said stationary support member not having an outer annular bearing surface.
 23. The device of claim 13, wherein each of said detector outer rings has an inner annular bearing surface concentric with said outer cylindrical surface; said inner member being arcuate and extending over more than 180 degrees of the outer ring, with a pivotal bearing to said support member being between its terminal ends; a single roller bearing on each terminal end of said inner member in engagement with the inner bearing surface of said outer ring, and a single roller bearing mounted on the central portion of said arcuate inner member and being in engagement with the inner bearing surface of said outer ring; the pivot bearing of said arcuate inner member being between said central roller bearing and one of said terminal end roller bearings.
 24. The apparatus of claim 13, wherein each said detector member outer rings has an inner annular bearing surface concentric with said outer cylindrical surface; said inner member being an arm having one end pivotally mounted to said support member, a single antifriction bearing on its central portion in engagement with the internal bearing surface of said outer ring, and a force transmitting terminal end at the opposite end from said pivotal bearing in engagement with said transducer means; further including two additional single roller bearings fixedly mounted on said support member in rolling engagement with the inner bearing surface of said outer ring; and said three roller bearings for each of said detectors being equally spaced around the inner periphery of said outer ring.
 25. The apparatus of claim 13, wherein each of said transducer means produces an output electrical control signal, and in combination with a control circuit, comprising: means for summing all of the electrical signals from said transducer means and producing therefrom a first reference signal and a second reference signal such that the ratio between the first reference signal and the second reference signal is equal to the ratio between the transverse width of a detector outer cylindrical surface and the transverse width of the plate edge in engagement with a detector outer cylindrical surface; means for individually comparing the transducer signals from the detectors that are in full transverse band engagement with said first reference signal to produce a corresponding plurality of output signals each proportional to the tension and thus flatness of the middle of the band at its corresponding measuring point; and means for individually comparing the transducer signals from the detectors that are partially engaging the edge of the band with said second reference signal to produce outputs correlated to the tension in the band edges and thus correlated to the flatness of the band edges.
 26. The apparatus of claim 13, in combination with a rolling mill comprising: a roll stand including opposed working rolls and back up rolls for the rolling reduction of the traveling band; said detectors being located to engage the band as it emerges from the working rolls; circuit means for processing the individual transducer output signals to produce corresponding plate flatness error signals; and means responsive to said flatness error signals for changing the contour of said working rolls to reduce the plate flatness error signals.
 27. A method for detecting the relaxed flatness profile across the transverse width of a band traveling under tension in the direction of its length, comprising the steps of: engaging one surface of the band plate throughout substantially its entire transverse width with a plurality of individual detectors having outer cylindrical surfaces transversely aligned with each other and of a common diameter to deflect the tRaveling band from its path of travel and produce a band tension component of force generally perpendicular to the tangent point of contact beween the band and the cylindrical surfaces of the detectors; freely rotating all of the outer cylindrical surfaces of the detectors independently of each other; supporting each of said freely rotatable detector cylindrical surfaces for pivotal movement about an axis spaced from the generally perpendicular to the line of action of the corresponding band tension component of force only within the confines of the corresponding cylindrical surface and thereby producing a band tension movement equal to said band tension component of force multiplied by the distance between said line of action and said axis; opposing said band tension moment with a reaction moment; producing within each cylindrical surface that is at least a portion of the reaction moment for each of said detectors; and comparing the band tension signals with each other to produce an indication of relaxed band profile. 